Primary Organ Anatomical Terms Primary Organ Anatomical Terms

32 PRIMARY ORGAN ANATOMICAL TERMS PRIMARY ORGAN ANATOMICAL TERMS

Bladder—receives urine from each kidney through a ureter. The bladder contains the urine until it is expelled from the body. Brain—divided into four unequal but distinct parts: pons varolii medulla oblongata, cerebellum, and cerebrum. Cerebellum—located in the lower rear portion of the brain; is divided into two halves. Cerebrum—comprises approximately 85 percent of the brain and is located across the top of the brain, from front to back. Colon—See large intestine. Cornea—the anterior transparent outer layer of the eye. It actually consists of five layers and is sometimes referred to as the “first coat.” Esophagus—extends from the base of the neck to the stomach and is used to transport food to the stomach. Gallbladder—works in conjunction with the liver and pancreas to assist in the digestive process; also produces bile, which empties into the intestine. Heart—a hollow muscular organ within the pericardium in the chest. It pumps blood from the body into the right side and into the lungs, where the blood is oxygenated and returned. The blood is then pumped through the left side of the heart and back into the body. Inner ear—referred to as the “Osseous Labyrinth”; consists of a series of structures including the vestibule, cochlea, and semicircular canals. Together, these structures operate to process vibrations from the tympanic membrane into sound. Kidneys—two glandular structures located in the posterior portion of the abdomen. They secrete urine for expulsion through the urinary tract system. Large intestine—also known as the colon. This organ is approximately 5 feet in length and connects the small intestine and the anus. It is segmented into four sections: ascending, transverse, descending, and sigmoid flexure. The large intestine processes chyle, distributes nutrition, and expels solid waste. Larynx—also known as the voice box; is a muscular structure that moves air across a series of ligaments to cre- ate sound. It is located between the base of the tongue and the top of the trachea. Lens—the transparent covering of concentric layers; transmits light and images to the retina. Liver—a large glandular organ. The primary function of the liver is to secrete bile used in the transport and digestion of food through the intestinal tract. Lungs—located on each side of the heart within the pericardium. The lungs infuse incoming oxygen into the oxygen-depleted blood coming from the heart through the spongy substance on the interior of the lungs. Small, hairlike structures filter the incoming oxygen. The newly oxygenated blood is then returned to the heart for dis- tribution into the body. Each lung is divided into two lobes. The right lung further subdivides the upper lobe into two smaller lobes. Medulla oblongata—one quadrant of the brain located in the lower portion of the brain between the foramen magnum and the lower border of the pons. Ovary—two organs found in the female abdominal cavity approaching the fallopian tubes extending from the uterus. During a normal reproductive cycle, the ovary will expel an ovum, commonly referred to as an egg. The egg then travels through the fallopian tube into the uterus, where fertilization can occur if seminal fluid is present. Palate—consists of two parts: hard and soft. The hard palate separates maxillary bone structure and is covered with a mucous membrane. The soft palate, which is behind the hard palate, is used as a muscle and mucous membrane structure along with the tongue to move nutrition toward the digestive tract. PRIMARY ORGAN ANATOMICAL TERMS 33

Pancreas—a gland that secretes pancreatic juices necessary for digestion. The pancreas, liver, and gallbladder all provide secretions that empty into the intestinal tract. It is responsible for the digestion of starch, emulsification of fats, and transformation of albuminoids to peptones. Penis—the male external organ used for reproduction and expulsion of urine. Pericardium—the membrane behind the sternum containing the heart and origin of the aorta and pulmonary artery. Pharynx—the fibrous mucous structure located behind the nose, mouth, and larynx; is approximately 4 1/2 inches in length. It flows digestive materials from the mouth to the esophagus. Pinna—the outer surface of the ear consisting of ridges and curvatures to transmit sound into the ear canal. Pleura—a highly sensitive, serious membrane that lines the exterior of the lung in a type of sac. Pons varolii—a quadrant of the brain making up the process by which the other three quadrants are connected. Prostate gland—located at the neck of the bladder and around the urethra; secrets the primary fluid compo- nent of semen. Retina—a complex structure of the eye containing 10 layers. It contains the end of the optic nerve and structures for processing light and color. Rectum—lies between the sigmoid flexure and the anus. It transports solid waste to the external opening of the body, where solid waste is expelled. Sclerotic—also referred to as the sclera; is a thick, protective membrane around the structures of the eye that enable sight. It is white in color and attaches to the muscles of the eye. Small intestine—made up of three distinct sections: duodenum, jejunum, ileum. This organ applies various secretions of the intestinal canal to form the nutrient portion of food known as chyle. Spleen—a ductless gland located in the abdomen; purpose is to process and break down red blood corpuscles that are no longer used by the body. Stomach—the principal portion of digestion; lies between the esophagus and the small intestine. Testes—two glandular organs suspended in the scrotum and attached by spermatic cords. The testes are responsible for the production of sperm. The vas deferens is the excretory duct of the testes, which releases semen through a long process and is released at the common ejaculatory duct. Tongue—used to move nutritional items into the digestive tract and secrete mucous to assist in this movement. Trachea—the air tube that carries oxygen into the body and carbon dioxide out of the body from the lungs. It is located immediately below the larynx. Tympanum—also known as the middle ear; contained within the temporal bone and transmits to the pharynx and inner ear through vibrations of the portion known as the membrane tympani. This is commonly referred to as the ear drum. Ureter—each kidney is connected to the bladder by this structure for the purpose of carrying urine from the kidney to the bladder. Uterus—the organ that produces the placental materials and cavity for support and containment of the fetus during gestation. When pregnancy does not occur within the normal menstrual cycle, the uterus expels the lining that has developed throughout the cycle for support of a fetus. Vagina—the canal that reaches from the uterus to the vulva. The vagina serves to receive seminal fluid for reproduction and as a means of expulsion of the uterine lining during the menstrual cycle and of a fetus and placenta during childbirth. Vulva—the external organs in the female associated with reproduction. These include the mons veneris, labia majora, labia minora, clitoris, meatus urinarius, orifice of the vagina, and perineum.